MPI-IO has many features that can help users achieve high performance.

The most important of these features are:

• The ability to specify noncontiguous accesses
• The collective I/O functions
• The ability to pass hints to the implementation

In particular, when accesses are noncontiguous, users must:

• Create derived datatypes
• Define file views
• Use the collective I/O functions

Use of these features is encouraged because I/O is expensive! It's best to let the system make tuning decisions on your behalf.